A Number 10 source told PinkNews.co.uk that they were “surprised and saddened” that the end of the parliamentary story concerning equal marriage in England and Wales failed to get sufficient coverage by the BBC’s main news programmes – especially given how contentious the subject had been.

A source close to Deputy Prime Minister Nick Clegg told PinkNews.co.uk: “Obviously no politician should be telling the media what news they cover, but it is a real shame that the national media chose largely to ignore the momentous point at which we finally saw same-sex couples given equal rights to get married.”

One government source added that they were “flabbergasted” at the lack of coverage.

Mr Sephton wrote: “You may well have missed this monumental event. After all the trouble and division stirred up in the early stages, once the groundbreaking legislation was passed interest, not least from the press, died away.

“Conservative Grassroots, a small group within the Tory party, had plentiful publicity when they gathered together just 15 former Conservative constituency chairmen to write a letter to David Cameron opposing equal marriage.

“However, when over 500 current local Conservative Association chairmen, deputy chairmen, officers and activists signed a letter supporting the Prime Minister, it hardly got a mention. Opinion polls consistently show the majority of the public support same-sex marriage, with even larger numbers among younger people.”

Mr Sephton added: “Now some on the fringe of the Tory are claiming the fall in numbers is due to the modernisation of the Conservative Party, and in particular its support for same-sex marriage. This could not be further from reality.

“There may be some older members lost due to policies such as gay marriage. But the fact is that membership of all political parties has been falling for decades and these memberships fluctuate according to which party is in government, and various other factors.”

He concluded: “I can tell you the people now joining the Conservative Party are joining because they see our local association is more in touch with them and with Britain as it really is in 2013. There are exceptions, but if other associations appear totally out of touch; or indeed militantly, and often offensively, oppose measures such as same sex marriage, it’s no wonder they are not getting new, younger members. As Baroness Jenkin told the Lords during the gay marriage debate, young people “just don’t understand what the fuss is about”.